Question 1 :
A slit of width a is illuminated by the red light of wavelength $6500 {A}^0$. If the first minimum falls at $\theta$ = 30$^{o}$, the value of a is
Question 2 :
A slit of width $a$ is illuminated by a monochromatic light of wavelength $650 \;nm$. The value of $a$ when the first minima falls at an angle of diffraction of $30^0$ is<br/>
Question 3 :
In a Young's double slit experiment the spacing between the slits is $0.3\ mm$ and the screen is kept at a distance of $1.5\ m$. The second bright fringe is found $6\ mm$ from the central fringe. The wavelength of the light used in the experiment is
Question 4 :
Two beams of light of intensity $I_1$ and $I_2$ interfere to give an interference pattern. If the ratio of maximum intensity to that of minimum intensity is $\dfrac{25}{9}$, then ratio of  $\displaystyle\frac{I_1}{I_2}$ is
Question 5 :
If one of the two slits of a Young's double slit experiment is painted over so that it transmits half the light intensity of the other, then:<br/>
Question 7 :
If the intensities of the two interfering beams in Young's double-slit experiment are I$_{1}$ and I$_{2}$, then the contrast between the maximum and minimum intensities is good when
Question 8 :
A plane wave of monochromatic light falls normally on a uniform thin film of oil which covers a glass plate. The wavelength of source can be varied continuously. Complete destructive interference is observed for $\lambda=5000\mathring { A } $ and $\lambda=1000\mathring { A } $ and for no other wavelength in between. If $\mu$ of oil is $1.3$ and that of glass is $1.5$, the thickness of the film will be<br>
Question 9 :
The distance between the slit and the bi-prism and between the bi-prism and the screen are $50cms$ each. The angle of the bi-prism is $179^0$ and its refractive index is $1.5$. If the distance between successive fringes is $0.0135cm$, then the wavelength of light is:
Question 10 :
In YDSE, find the missing wavelength in front of one of the slits.
Question 11 :
Interference fringes were produced in Youngs double slit experiment using light of wavelength $5000\,A$. When a film of thickness $2.5\times 10^{-3}\ cm$ was placed in front of one of the slits, then the fringe pattern shifted by a distance equal to $20$ fringe widths. The refractive index of the material of the film is
Question 12 :
A thin film with an index of refraction of $1.50$ coats a glass lens. The index of refraction of the glass is $1.60$.<br>What is the thinnest coating of film that will provide for very strongly reflected $546 nm$ light (constructive thin film interference)?
Question 13 :
A slit of width $a$ is illuminated by white light. The first minimum for red light ($\lambda$ = 6500 $\overset{o}{A}$) will fall at $\displaystyle\theta$ = 30$^{o}$ when $a$ will be
Question 14 :
In an interference experiment, third bright fringe is obtained at a point on the screen with a light of $700nm$. What should be the wavelength of the light source in order to obtain $5th$ bright fringe at the same point?<br>
Question 15 :
A ray of light is incident on the surface of plateof glass of refractive index 1.5 at the polarisingangle. The angle of refraction of the ray will be.
Question 16 :
A beam of unpolarized light is passed first through a tourmaline crystal $A$ and then through another tourmaline crystal $B$ oriented so that its principal plane is parallel to that of $A$. The intensity of final emergent light is $I$. If $A$ is rotated by $45^0$ on a plane, perpendicular to the direction of incident ray, then intensity of emergent light will be
Question 17 :
In Young's double slit experiment a minima is observed when path difference between the interfering beam is
Question 18 :
If accelerating potential increases from $20\ KV$ to $80\ KV$ in an electron microscope, its resolvingpower $R$ would change to<br>
Question 19 :
Light of wavelength $6000\ A$ <br> $^{\circ}$ from a distant source falls on a slit $0.5\ mm$ wide. The distance between two dark bands on each side of the central bright band of the diffraction pattern observed on a screen placed at a distance $2\ m$ from the slit is:<br/>
Question 20 :
A monochromatic plane wave of speed c and wavelength $\lambda$ is diffracted at a small aperture. The diagram illustrates successive wave fronts.<br>After what time will some portion of the wave front GH reach point P?<br>
Question 21 :
The condition for observing Fraunhoffer diffraction from a single slit is that the light wavefront incident on the slit should be
Question 23 :
The resolving power of an electron microscope operated at 16 kV is R. The resolving power of the electron microscope when operated at 4 kV is<br>
Question 24 :
In the Young's double slit experiment two light beams of wavelengths $\lambda=6000A^o$ and $\lambda=4800A^o$ are used. The distance between two slits is $2.5mm$. The distance between slits and the screen is $1.5m$. Thedistance of seventh dark fringes for $\lambda_2$ from central maximum will be<br>
Question 25 :
Choose the Correct answer from alternative given.<br/>Light from two coherent sources of the same amplitude A  and wavelength $\lambda$ illuminates the screen. The intensity of the central maxima is $I_0$ . If the sources were incoherent, the intensity at the same point will be then:<br/>
Question 26 :
The maximum number of possible interference maxima for slit-separation equal to twice the wavelength in Young's double-slit experiment, is; 
Question 28 :
In Young's double salt experiment, if the slit widths are in the ratio $1:9$ then the ratio of the intensity at minima to the at maxima will be
Question 29 :
In Young's double slit experiment, while using a source of light of wavelength 5000Å, the fringe width obtained is 0.6 cm. If the distance between the screen and slit is reduced to half, the wavelength of the source to get fringes 0.003 m wide is :<br/>
Question 31 :
Two coherent monochromatic light beams of intensities $4l$ and $9l$ are superimposed. The maximum and minimum possible intensities in the resulting beam are
Question 32 :
In the phenomena of diffraction of light, when blue light is used in the experiment in spite of red light, then
Question 33 :
If YDSE is immersed in a liquid of refractive index $'\mu\ '$ then the fringe width $'\beta\ '$
Question 34 :
A beam of light of $\lambda = 600 nm$ from a distant source falls on a single slit 1 mm wide and the resultingdiffraction pattern is observed on a screen 2m away. The distance between first dark fringes on either side ofthe central bright fringe is
Question 35 :
Light from two coherent sources of the same amplitude $A$ and wavelength $\lambda$ illuminates the screen. The intensity of the central maximum is $I_0$. If the sources were incoherent, the intensity at the same point will be.
Question 36 :
The ratio of the intensity at the centre of a bright fringe to the intensity at a point one-quarter of the distance between two fringes from the centre is :
Question 37 :
 Intensity at center in YDSE is $I_0$. If one slit is covered, then intensity at center will be:
Question 38 :
Consider an YDSE that has different slits width, as a result, amplitudes of waves from two slits are $A$ and $2A$, respectively. If $I_{0}$ be the maximum intensity of the interference pattern, then intensity of the pattern at apoint where phase difference between waves is $\phi$ is :
Question 39 :
Tenth fringe of wavelength $4000A^o$ coincides with $8th$ fringes of wavelength $\lambda$. Then $\lambda$ is<br>
Question 40 :
In a Fresnel's diffraction arrangement, the screen is at a distance of $2$ meter from a circular aperture. It is found that for light of wavelength $\lambda_{1}$ and $\lambda_{2},$ the radius of $4\ th$ zone for $\lambda_{1}$ coincides with the radius of $5^{th}$ zone for $\lambda_{2}.$ then the ratio $\lambda_{1}:\lambda_{2}$ is
